The present invention relates to the art of sulfur extraction and more in particular to the art of removing sulfur from a hot fuel gas at low temperatures with high heat recovery and thermal efficiency.
Coal with a high sulfur content is abundant. Regrettably, the sulfur in the coal makes the coal unsuitable as a fuel, for sulfur is an unacceptable pollutant.
The gasification coal to convert it to a gaseous fuel has been explored and is considered highly desirable because the gaseous fuel is more flexible than the solid coal. In either state, however, the fuel value of the coal cannot be used if sulfur it contains cannot be economically reduced to an acceptable level. Existing sulfur removal processes require relatively low temperatures. Thus, it would be necessary in implementing existing processes to cool the hot gases from gasification prior to sulfur removal. A large percentage of the considerable sensible heat of the hot gases lost during cooling must be usefully reclaimed for the process to be attractive.
The present invention is directed to the extraction of sulfur from gasified hydrocarbon values at low temperatures and with a high degree of heat recovery.